I don't know it this has been posted, but I just discovered it, and I am loving it.

If you shoot regular video at 4K (suppose other qualities work too) and 120fps, then import it to your iPhone, you will end up with a video that appears as shot in slow motion, natively on the iPhone, has the sliders to adjust when slo-mo starts and ends, and MORE IMPORTANTLY, it has sound!

I hope this is not a bug, but a feature

That is nice.
Never knew that!

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